Re: [PATCH v9 1/3] s390x: KVM: ipte lock for SCA access should be contained in KVM
From: Pierre Morel
Date: Mon May 16 2022 - 10:10:14 EST
On 5/12/22 13:32, Janosch Frank wrote:
On 5/6/22 11:24, Pierre Morel wrote:
The former check to chose between SIIF or not SIIF can be done
using the sclp.has_siif instead of accessing per vCPU structures
Maybe replace this paragraph with:
We can check if SIIF is enabled by testing the sclp_info struct instead
of testing the sie control block eca variable. sclp.has_ssif is the only
requirement to set ECA_SII anyway so we can go straight to the source
for that.
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
OK, thanks,
Regards,
Pierre
When accessing the SCA, ipte lock and ipte_unlock do not need
to access any vcpu structures but only the KVM structure.
Let's simplify the ipte handling.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
arch/s390/kvm/gaccess.c | 96 ++++++++++++++++++++---------------------
arch/s390/kvm/gaccess.h | 6 +--
arch/s390/kvm/priv.c | 6 +--
3 files changed, 54 insertions(+), 54 deletions(-)
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index d53a183c2005..0e1f6dd31882 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -262,77 +262,77 @@ struct aste {
/* .. more fields there */
};
-int ipte_lock_held(struct kvm_vcpu *vcpu)
+int ipte_lock_held(struct kvm *kvm)
{
- if (vcpu->arch.sie_block->eca & ECA_SII) {
+ if (sclp.has_siif) {
int rc;
- read_lock(&vcpu->kvm->arch.sca_lock);
- rc = kvm_s390_get_ipte_control(vcpu->kvm)->kh != 0;
- read_unlock(&vcpu->kvm->arch.sca_lock);
+ read_lock(&kvm->arch.sca_lock);
+ rc = kvm_s390_get_ipte_control(kvm)->kh != 0;
+ read_unlock(&kvm->arch.sca_lock);
return rc;
}
- return vcpu->kvm->arch.ipte_lock_count != 0;
+ return kvm->arch.ipte_lock_count != 0;
}
-static void ipte_lock_simple(struct kvm_vcpu *vcpu)
+static void ipte_lock_simple(struct kvm *kvm)
{
union ipte_control old, new, *ic;
- mutex_lock(&vcpu->kvm->arch.ipte_mutex);
- vcpu->kvm->arch.ipte_lock_count++;
- if (vcpu->kvm->arch.ipte_lock_count > 1)
+ mutex_lock(&kvm->arch.ipte_mutex);
+ kvm->arch.ipte_lock_count++;
+ if (kvm->arch.ipte_lock_count > 1)
goto out;
retry:
- read_lock(&vcpu->kvm->arch.sca_lock);
- ic = kvm_s390_get_ipte_control(vcpu->kvm);
+ read_lock(&kvm->arch.sca_lock);
+ ic = kvm_s390_get_ipte_control(kvm);
do {
old = READ_ONCE(*ic);
if (old.k) {
- read_unlock(&vcpu->kvm->arch.sca_lock);
+ read_unlock(&kvm->arch.sca_lock);
cond_resched();
goto retry;
}
new = old;
new.k = 1;
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
- read_unlock(&vcpu->kvm->arch.sca_lock);
+ read_unlock(&kvm->arch.sca_lock);
out:
- mutex_unlock(&vcpu->kvm->arch.ipte_mutex);
+ mutex_unlock(&kvm->arch.ipte_mutex);
}
-static void ipte_unlock_simple(struct kvm_vcpu *vcpu)
+static void ipte_unlock_simple(struct kvm *kvm)
{
union ipte_control old, new, *ic;
- mutex_lock(&vcpu->kvm->arch.ipte_mutex);
- vcpu->kvm->arch.ipte_lock_count--;
- if (vcpu->kvm->arch.ipte_lock_count)
+ mutex_lock(&kvm->arch.ipte_mutex);
+ kvm->arch.ipte_lock_count--;
+ if (kvm->arch.ipte_lock_count)
goto out;
- read_lock(&vcpu->kvm->arch.sca_lock);
- ic = kvm_s390_get_ipte_control(vcpu->kvm);
+ read_lock(&kvm->arch.sca_lock);
+ ic = kvm_s390_get_ipte_control(kvm);
do {
old = READ_ONCE(*ic);
new = old;
new.k = 0;
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
- read_unlock(&vcpu->kvm->arch.sca_lock);
- wake_up(&vcpu->kvm->arch.ipte_wq);
+ read_unlock(&kvm->arch.sca_lock);
+ wake_up(&kvm->arch.ipte_wq);
out:
- mutex_unlock(&vcpu->kvm->arch.ipte_mutex);
+ mutex_unlock(&kvm->arch.ipte_mutex);
}
-static void ipte_lock_siif(struct kvm_vcpu *vcpu)
+static void ipte_lock_siif(struct kvm *kvm)
{
union ipte_control old, new, *ic;
retry:
- read_lock(&vcpu->kvm->arch.sca_lock);
- ic = kvm_s390_get_ipte_control(vcpu->kvm);
+ read_lock(&kvm->arch.sca_lock);
+ ic = kvm_s390_get_ipte_control(kvm);
do {
old = READ_ONCE(*ic);
if (old.kg) {
- read_unlock(&vcpu->kvm->arch.sca_lock);
+ read_unlock(&kvm->arch.sca_lock);
cond_resched();
goto retry;
}
@@ -340,15 +340,15 @@ static void ipte_lock_siif(struct kvm_vcpu *vcpu)
new.k = 1;
new.kh++;
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
- read_unlock(&vcpu->kvm->arch.sca_lock);
+ read_unlock(&kvm->arch.sca_lock);
}
-static void ipte_unlock_siif(struct kvm_vcpu *vcpu)
+static void ipte_unlock_siif(struct kvm *kvm)
{
union ipte_control old, new, *ic;
- read_lock(&vcpu->kvm->arch.sca_lock);
- ic = kvm_s390_get_ipte_control(vcpu->kvm);
+ read_lock(&kvm->arch.sca_lock);
+ ic = kvm_s390_get_ipte_control(kvm);
do {
old = READ_ONCE(*ic);
new = old;
@@ -356,25 +356,25 @@ static void ipte_unlock_siif(struct kvm_vcpu *vcpu)
if (!new.kh)
new.k = 0;
} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
- read_unlock(&vcpu->kvm->arch.sca_lock);
+ read_unlock(&kvm->arch.sca_lock);
if (!new.kh)
- wake_up(&vcpu->kvm->arch.ipte_wq);
+ wake_up(&kvm->arch.ipte_wq);
}
-void ipte_lock(struct kvm_vcpu *vcpu)
+void ipte_lock(struct kvm *kvm)
{
- if (vcpu->arch.sie_block->eca & ECA_SII)
- ipte_lock_siif(vcpu);
+ if (sclp.has_siif)
+ ipte_lock_siif(kvm);
else
- ipte_lock_simple(vcpu);
+ ipte_lock_simple(kvm);
}
-void ipte_unlock(struct kvm_vcpu *vcpu)
+void ipte_unlock(struct kvm *kvm)
{
- if (vcpu->arch.sie_block->eca & ECA_SII)
- ipte_unlock_siif(vcpu);
+ if (sclp.has_siif)
+ ipte_unlock_siif(kvm);
else
- ipte_unlock_simple(vcpu);
+ ipte_unlock_simple(kvm);
}
static int ar_translation(struct kvm_vcpu *vcpu, union asce *asce,
u8 ar,
@@ -1075,7 +1075,7 @@ int access_guest_with_key(struct kvm_vcpu *vcpu,
unsigned long ga, u8 ar,
try_storage_prot_override = storage_prot_override_applicable(vcpu);
need_ipte_lock = psw_bits(*psw).dat && !asce.r;
if (need_ipte_lock)
- ipte_lock(vcpu);
+ ipte_lock(vcpu->kvm);
/*
* Since we do the access further down ultimately via a move
instruction
* that does key checking and returns an error in case of a
protection
@@ -1113,7 +1113,7 @@ int access_guest_with_key(struct kvm_vcpu *vcpu,
unsigned long ga, u8 ar,
rc = trans_exc(vcpu, rc, ga, ar, mode, prot);
out_unlock:
if (need_ipte_lock)
- ipte_unlock(vcpu);
+ ipte_unlock(vcpu->kvm);
if (nr_pages > ARRAY_SIZE(gpa_array))
vfree(gpas);
return rc;
@@ -1185,10 +1185,10 @@ int check_gva_range(struct kvm_vcpu *vcpu,
unsigned long gva, u8 ar,
rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode);
if (rc)
return rc;
- ipte_lock(vcpu);
+ ipte_lock(vcpu->kvm);
rc = guest_range_to_gpas(vcpu, gva, ar, NULL, length, asce, mode,
access_key);
- ipte_unlock(vcpu);
+ ipte_unlock(vcpu->kvm);
return rc;
}
@@ -1451,7 +1451,7 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu,
struct gmap *sg,
* tables/pointers we read stay valid - unshadowing is however
* always possible - only guest_table_lock protects us.
*/
- ipte_lock(vcpu);
+ ipte_lock(vcpu->kvm);
rc = gmap_shadow_pgt_lookup(sg, saddr, &pgt, &dat_protection,
&fake);
if (rc)
@@ -1485,7 +1485,7 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu,
struct gmap *sg,
pte.p |= dat_protection;
if (!rc)
rc = gmap_shadow_page(sg, saddr, __pte(pte.val));
- ipte_unlock(vcpu);
+ ipte_unlock(vcpu->kvm);
mmap_read_unlock(sg->mm);
return rc;
}
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index 1124ff282012..9408d6cc8e2c 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -440,9 +440,9 @@ int read_guest_real(struct kvm_vcpu *vcpu,
unsigned long gra, void *data,
return access_guest_real(vcpu, gra, data, len, 0);
}
-void ipte_lock(struct kvm_vcpu *vcpu);
-void ipte_unlock(struct kvm_vcpu *vcpu);
-int ipte_lock_held(struct kvm_vcpu *vcpu);
+void ipte_lock(struct kvm *kvm);
+void ipte_unlock(struct kvm *kvm);
+int ipte_lock_held(struct kvm *kvm);
int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu,
unsigned long gra);
/* MVPG PEI indication bits */
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 5beb7a4a11b3..0e8603acc105 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -443,7 +443,7 @@ static int handle_ipte_interlock(struct kvm_vcpu
*vcpu)
vcpu->stat.instruction_ipte_interlock++;
if (psw_bits(vcpu->arch.sie_block->gpsw).pstate)
return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
- wait_event(vcpu->kvm->arch.ipte_wq, !ipte_lock_held(vcpu));
+ wait_event(vcpu->kvm->arch.ipte_wq, !ipte_lock_held(vcpu->kvm));
kvm_s390_retry_instr(vcpu);
VCPU_EVENT(vcpu, 4, "%s", "retrying ipte interlock operation");
return 0;
@@ -1472,7 +1472,7 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
access_key = (operand2 & 0xf0) >> 4;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
- ipte_lock(vcpu);
+ ipte_lock(vcpu->kvm);
ret = guest_translate_address_with_key(vcpu, address, ar, &gpa,
GACC_STORE, access_key);
@@ -1509,7 +1509,7 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
}
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
- ipte_unlock(vcpu);
+ ipte_unlock(vcpu->kvm);
return ret;
}
--
Pierre Morel
IBM Lab Boeblingen